Vehicular fuel cell system and method of controlling the same

ABSTRACT

A vehicular fuel cell system includes a collision detector configured to detect collision on the front and rear sides of a vehicle, a high voltage unit arranged on one side of the front and rear sides of the vehicle, a high voltage controller arranged on the one side and configured to control the high voltage unit, a hydrogen supply unit arranged on the other side of the front and rear sides of the vehicle and configured to supply hydrogen to a fuel cell stack, and a supply valve controller arranged on the other side and configured to control a hydrogen supply valve, the hydrogen supply valve being configured to shut off a supply path of hydrogen from the hydrogen supply unit to the fuel cell stack.

The disclosure of Japanese Patent Application No. 2015-245902 filed onDec. 17, 2015 including the specification, drawings and abstract isincorporated herein by reference in its entirety.

BACKGROUND

1. Technical Field

The disclosure relates to a vehicular fuel cell system and a method ofcontrolling the same.

2. Description of Related Art

For example, a vehicular fuel cell system which, if collision of avehicle is detected, shuts off the fuel supply to a fuel cell stack by ashut-off valve and shuts off a power system of the fuel cell stack by arelay is known (see Japanese Patent Application Publication No.2007-335184 (JP 2007-335184 A)).

SUMMARY

However, in the above-described vehicular fuel cell system, for example,a controller which controls the relay of the power system and acontroller which controls the shut-off valve of the fuel supply arerespectively arranged at the front or rear of the vehicle. If collisionat the front or rear of the vehicle occurs, the controllers may fail andmay not function. In this case, there is a concern that shut-off of thefuel supply to the fuel cell stack and shut-off of the power system ofthe fuel cell stack are not properly performed. Accordingly, there is aneed for reliably stopping the function of a control target, such asshut-off of the fuel supply to the fuel cell stack or shut-off of thepower system of the fuel cell stack, even in a case where vehiclecollision occurs.

The disclosure provides a vehicular fuel cell system and a method ofcontrolling the same capable of reliably stopping the function of acontrol target even in a case where vehicle collision occurs.

A first aspect of the disclosure relates to a vehicular fuel cell systemincluding a collision detector configured to detect collision on frontand rear sides of a vehicle, a high voltage unit arranged on one side ofthe front and rear sides of the vehicle and having a high voltage, ahigh voltage controller arranged on the one side and configured tocontrol the high voltage unit, a hydrogen supply unit arranged on theother side of the front and rear sides of the vehicle and configured tosupply hydrogen to a fuel cell stack, and a supply valve controllerarranged on the other side and configured to control a hydrogen supplyvalve, the hydrogen supply valve being configured to shut off a supplypath of hydrogen from the hydrogen supply unit to the fuel cell stack.If collision is detected by the collision detector, the supply valvecontroller on the other side performs discharging control fordischarging the high voltage unit on the one side, and the high voltagecontroller on the one side performs shut-off control for bringing thehydrogen supply valve on the other side into a closed state.

According to this aspect, in a case where collision occurs on one sideof the vehicle, and the high voltage controller on one side fails, thesupply valve controller which is at a location separated from thecollision part on the other side of the vehicle unsusceptible to animpact of collision reliably performs the discharging control fordischarging the high voltage unit. Furthermore, in a case wherecollision occurs on the other side of the vehicle, and the supply valvecontroller on the other side fails, the high voltage controller which isat a location separated from the collision part on one side of thevehicle unsusceptible to an impact of collision reliably performs theshutoff control for bringing the hydrogen supply valve into the closedstate. That is, it is possible to reliably stop the function of acontrol target even in a case where vehicle collision occurs.

A proximity sensor configured to detect distance information withrespect to an object may be provided on each of the one side and theother side in the periphery of the vehicle, when the collision detectordetects collision on the one side based on the distance information fromthe proximity sensor on the one side, the supply valve controller on theother side may perform the discharging control for discharging the highvoltage unit according to a detection result of the collision detectorand when the collision detector detects collision on the other sidebased on the distance information from the proximity sensor on the otherside, the high voltage controller on the one side may perform theshut-off control for bringing the hydrogen supply valve into the closedstate according to the detection result of the collision detector.

With this, only the control on a side, on which collision is detected,between the discharging control of the high voltage unit on one side andthe shut-off control of the hydrogen supply valve on the other side isexecuted by determining a collision location of the vehicle using theproximity sensors. With this, it is possible to stop only the functionof the side, on which collision is detected, between the high voltageunit on one side and the hydrogen supply unit on the other side, and tocontinue the function of a side on which collision is not detected.

The vehicular fuel cell system may further include a travelingdetermination unit configured to determine whether or not the vehicle isin a traveling-disabled state, and a notification unit configured togive a user notification that the vehicle is in the traveling-disabledstate, and when the collision detector detects collision on the oneside, the supply valve controller on the other side may perform thedischarging control for discharging the high voltage unit according tothe detection result of the collision detector, the travelingdetermination unit may determine that the vehicle is in thetraveling-disabled state according to the detection result of thecollision detector, and the notification unit may give notification tothe effect that the vehicle is in the traveling-disabled state.

With this, when collision on one side is detected, it is possible togive a user notification to the effect that the vehicle is in thetraveling-disabled state and to prevent unreasonable retreat travelingwhile reliably performing the discharging control of the high voltageunit on one side.

The high voltage controller may be provided closer to a vehicle centerthan the high voltage unit in a front-rear direction of the vehicle.

The hydrogen supply unit may include a hydrogen storage tank, and thesupply valve controller may be provided closer to a vehicle center thanthe hydrogen storage tank in a front-rear direction of the vehicle.

Only the supply valve controller may perform the discharging control ofthe high voltage unit, and only the high voltage controller may performthe shut-off control of the hydrogen supply valve.

The high voltage unit may include a battery.

A second aspect of the disclosure relates to a method of controlling avehicular fuel cell system including a high voltage unit arranged on oneside of front and rear sides of the vehicle and having a high voltage, ahigh voltage controller arranged on the one side and configured tocontrol the high voltage unit, a hydrogen supply unit arranged on theother side of the front and rear sides of the vehicle and configured tosupply hydrogen to a fuel cell stack, and a supply valve controllerarranged on the other side and configured to control a hydrogen supplyvalve, the hydrogen supply valve being configured to shut off a supplypath of hydrogen from the hydrogen supply unit to the fuel cell stack.In this control method, when collision on the one side or the other sideis detected, the supply valve controller on the other side performsdischarging control for discharging the high voltage unit on the oneside, and the high voltage controller on the one side performs shut-offcontrol for bringing the hydrogen supply valve on the other side into aclosed state.

According to the disclosure, it is possible to provide a vehicular fuelcell system and a method of controlling the same capable of reliablystopping the function of a control target even in a case where vehiclecollision occurs.

BRIEF DESCRIPTION OF THE DRAWINGS

Features, advantages, and technical and industrial significance ofexemplary embodiments of the disclosure will be described below withreference to the accompanying drawings, in which like numerals denotelike elements, and wherein:

FIG. 1 is a block diagram showing a schematic system configuration of avehicular fuel cell system according to a first embodiment of thedisclosure;

FIG. 2 is a flowchart showing a method of controlling the vehicular fuelcell system according to the first embodiment of the disclosure;

FIG. 3 is a block diagram showing a schematic system configuration of avehicular fuel cell system according to a second embodiment of thedisclosure;

FIG. 4 is a block diagram showing a schematic system configuration of avehicular fuel cell system according to a third embodiment of thedisclosure;

FIG. 5 is a flowchart showing a control processing flow of the vehicularfuel cell system according to the third embodiment of the disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, an embodiment of the disclosure will be described referringto the drawings. FIG 1 is a block diagram showing a schematic systemconfiguration of a vehicular fuel cell system according to a firstembodiment.

A vehicular fuel cell system 10 according to the first embodiment ismounted in a fuel cell vehicle 100 in which a fuel cell stack 1 ismounted as an on-vehicle power supply. The vehicular fuel cell system 10according to the first embodiment includes a collision detector 2 whichdetects collision on the front and rear sides of the vehicle, a highvoltage unit 3 (in this embodiment, a battery) which is arranged on oneside of the front and rear sides of the vehicle and has a high voltage,a high voltage controller 4 which is arranged on one side and controlsthe high voltage unit 3, a hydrogen supply unit 5 which is arranged onthe other side of the front and rear sides of the vehicle and supplieshydrogen to the fuel cell stack 1, and a supply valve controller 8 whichis arranged on the other side and controls a hydrogen supply valve 7configured to shut off a supply path 6 of hydrogen from the hydrogensupply unit 5 to the fuel cell stack 1.

The collision detector 2 is, for example, an airbag control device whichcontrols an airbag. The airbag control device is provided near thevehicle center inside an occupant space 101 unsusceptible to an impactof collision from all directions of the vehicle. The airbag controldevice can detect collision on the front or rear side of the vehiclebased on an acceleration detected by an internal acceleration sensor.For example, the airbag control device detects collision on the front orrear side of the vehicle if the acceleration of the acceleration sensoris equal to or greater than a predetermined threshold.

For example, the collision detector 2 and the high voltage controller 4are connected to each other through a wiring 9 passing through thevehicle center unsusceptible to an impact of vehicle collision.Similarly, the collision detector 2 and the supply valve controller 8are connected to each other through a wiring 9 passing though thevehicle center unsusceptible to an impact of vehicle collision. Ifcollision on the on the front and rear sides of the vehicle is detected,the collision detector 2 outputs a collision signal to the high voltagecontroller 4 and the supply valve controller 8.

The high voltage unit 3 is arranged, for example, on the front rightside of the vehicle. The high voltage unit 3 is a high voltage line (asmoothing capacitor and the like) of a power controller (PCU) whichrequires high voltage discharging. The high voltage unit 3 is providedwith a high voltage line having a high voltage, or the like.

The high voltage controller 4 is arranged, for example, on the frontright side of the vehicle, and is connected to the high voltage unit 3through a signal line. The high voltage controller 4 is arranged at alocation adjacent to the occupant space 101 on the front side of thevehicle with little impact at the time of collision. The high voltagecontroller 4 is arranged in the vicinity of the high voltage unit 3 forreduction in noise of the signal line and reduction in weight. The highvoltage unit 3 and the high voltage controller 4 may be arranged on thefront left side of the vehicle.

The hydrogen supply unit 5 is arranged, for example, on the rear side ofthe vehicle. The hydrogen supply unit 5 includes a device which supplieshydrogen gas to an anode of the fuel cell stack 1 (a hydrogen storagetank 51 which stores hydrogen gas, a reformer which reforms raw fuel tohydrogen-rich gas, and the like) and auxiliaries (a regulator, ahumidifier, and the like).

The fuel cell stack 1 supplies hydrogen gas and oxidized gas to anelectrolyte/electrode catalyst composite to cause an electrochemicalreaction and to convert chemical energy to electric energy. The fuelcell stack 1 has, for example, a stack structure in which a plurality ofsingle cells each having an anode and a cathode arranged to face eachother on both surfaces of a solid polyelectrolyte membrane and theoutside thereof sandwiched between a pair of separators are laminated.

The hydrogen supply unit 5 supplies hydrogen gas to the anode of thefuel cell stack 1 through the supply path 6. The supply path 6 isprovided with the hydrogen supply valve 7 which shuts off the supplypath 6 of hydrogen from the hydrogen storage tank 51 of the hydrogensupply unit 5 to the fuel cell stack 1. The hydrogen supply valve 7 isprovided, for example, in the vicinity of the hydrogen storage tank 51of the hydrogen supply unit 5 on the rear left side of the vehicle. Thehydrogen supply valve 7 is opened or closed in response to a controlinstruction from the supply valve controller 8.

The supply valve controller 8 is arranged, for example, on the rear leftside of the vehicle, and is connected to the hydrogen supply valve 7through a signal line. The supply valve controller 8 is arranged at alocation adjacent to the occupant space 101 on the rear side of thevehicle with little impact at the time of collision. The supply valvecontroller 8 is provided in the vicinity of the hydrogen supply valve 7for reduction in noise of the signal line and reduction of weight. Thehigh voltage controller 4 and the supply valve controller 8 are arrangeddiagonally on the vehicle. The hydrogen supply valve 7 and the supplyvalve controller 8 may be arranged on the rear right side of thevehicle.

The high voltage controller 4 and the supply valve controller 8 areconstituted by hardware, for example, centering on a microcomputerhaving a central processing unit (CPU) which performs computationprocessing, control processing, and the like, a read only memory (ROM)which stores a computation program, a control program, and the like tobe executed by the CPU, a random access memory (RAM) which storesvarious kinds of data or the like, an interface unit (I/F) whichperforms an input/output of signals with the outside. The CPU, the ROM,the RAM, and the interface unit are connected to one another through adata bus or the like.

On the other hand, for example, in a case where an object collidesagainst the front of the vehicle, the high voltage line or the like ofthe high voltage unit arranged on the front side of the vehicle may beexposed. For this reason, at the time of vehicle collision, dischargingof the high voltage unit needs to be performed, and the voltage of thehigh voltage line needs to be reliably dropped. However, in the relatedart, the high voltage controller which controls the discharging of thehigh voltage unit is arranged on the front side of the collided vehicle.For this reason, there is a concern that failure or the like of the highvoltage controller is caused by an impact at the time of collision, andit is not possible to properly control the discharging of the highvoltage unit.

Similarly, in a case where an object collides against the rear of thevehicle, hydrogen may leak from the hydrogen supply unit on the rearside of the vehicle. For this reason, at the time of vehicle collision,the hydrogen supply valve of the hydrogen storage tank needs to bebrought into a closed state to reliably prevent hydrogen leakage.However, in the related art, the supply valve controller which controlsthe hydrogen supply valve is arranged on the rear side of the collidedvehicle. For this reason, there is a concern that failure or the like ofthe supply valve controller is caused by an impact at the time ofcollision, and it is not possible to properly control the hydrogensupply valve.

In contrast, in the vehicular fuel cell system 10 according to the firstembodiment, if collision on one side or the other side of the front andrear sides of the vehicle is detected by the collision detector 2, thesupply valve controller 8 on the other side performs control fordischarging the high voltage unit 3, and the high voltage controller 4on one side performs control for bringing the hydrogen supply valve 7into the closed state. With this, in a case where collision occurs onone side of the vehicle and the high voltage controller 4 on one sidefails, the supply valve controller 8 which is at a location separatedfrom a collision part on the other side of the vehicle unsusceptible toan impact of collision reliably performs control for discharging thehigh voltage unit 3. In addition, even in a case where collision occurson the other side of the vehicle and the supply valve controller 8 onthe other side fails, the high voltage controller 4 which is at alocation separated from a collision part on one side of the vehicleunsusceptible to an impact of collision reliably performs control forbringing the hydrogen supply valve 7 into the closed state. That is,even in a case where vehicle collision occurs, it is possible toreliably stop the function of a control target.

Both of the front and rear sides of the vehicle are rarely brokensimultaneously even in double collision. In addition, in the firstembodiment, the high voltage controller 4 and the supply valvecontroller 8 are arranged at locations adjacent to the occupant space101 on the front and rear sides of the vehicle with little impact at thetime of collision. For this reason, the high voltage controller 4 andthe supply valve controller 8 hardly fail simultaneously due tocollision. Accordingly, in the first embodiment, as described above,even in a case where collision occurs, at least one of the high voltagecontroller 4 or the supply valve controller 8 reliably functionsnormally, and the discharging control of the high voltage unit 3 or theshut-off control of the hydrogen supply valve 7 can be performed on theside which reliably functions normally.

In order to reliably execute the discharging control of the high voltageunit 3 and the shut-off control of the hydrogen supply valve 7 at thetime of vehicle collision, for example, a case where the high voltagecontroller and the supply valve controller respectively have thefunctions of the discharging control of the high voltage unit and theshut-off control of the hydrogen supply valve is considered. However, inthis case, the configurations of the high voltage controller and thesupply valve controller become redundant, and a double wiring isprovided for the high voltage unit and the hydrogen supply valve,causing an increase in costs and weight.

In contrast, the vehicular fuel cell system 10 according to the firstembodiment has a simple configuration in which only the supply valvecontroller 8 has the function of the discharging control of the highvoltage unit 3, and only the high voltage controller 4 has the functionof the shut-off control of the hydrogen supply valve 7. A double wiringdoes not need to be provided for the high voltage unit 3 and thehydrogen supply valve 7. For this reason, it is possible to achievereduction in costs and weight of the vehicular fuel cell system 10.

For example, if collision on the front or rear side of the vehicle isdetected, the collision detector 2 transmits a collision signal to thehigh voltage controller 4 on the front side of the vehicle and thesupply valve controller 8 on the rear side of the vehicle. At this time,collision on the front side of the vehicle may cause failure or the likein the high voltage controller 4 on the front side of the vehicle.However, the normal supply valve controller 8 on the rear side of thevehicle performs control for discharging the high voltage unit 3 bytransmitting a control signal to the high voltage unit 3 in response tothe collision signal from the collision detector 2. With this, even in acase where collision occurs on the front side of the vehicle, the normalsupply valve controller 8 on the rear side of the vehicle can reliablyperform control for discharging the high voltage unit 3.

On the other hand, collision on the rear side of the vehicle may causefailure or the like in the supply valve controller 8 on the rear side ofthe vehicle. However, the normal high voltage controller 4 on the frontside of the vehicle performs control for brining the hydrogen supplyvalve 7 into the closed state by transmitting a control signal to thehydrogen supply valve 7 in response to the collision signal from thecollision detector 2. With this, even in a case where collision occurson the rear side of the vehicle, the normal high voltage controller 4 onthe front side of the vehicle can reliably perform control for bringingthe hydrogen supply valve 7 into the closed state.

FIG. 2 is a flowchart showing a method of controlling the vehicular fuelcell system according to the first embodiment. If an object collidesagainst the vehicle (Step S101), the collision detector 2 detectscollision on the front or rear side of the vehicle (Step S102).

If collision on the front or rear side of the vehicle is detected, thecollision detector 2 transmits the collision signal to the high voltagecontroller 4 on the front side of the vehicle and the supply valvecontroller 8 on the rear side of the vehicle (Step S103). The supplyvalve controller 8 on the rear side of the vehicle performs control fordischarging the high voltage unit 3 on the front side of the vehicle inresponse to the collision signal from the collision detector 2 (StepS104). The high voltage controller 4 on the front side of the vehicleperforms control for bringing the hydrogen supply valve 7 on the rearside of the vehicle into the closed state in response to the collisionsignal from the collision detector 2 (Step S105).

As described above, in the vehicular fuel cell system 10 according tothe first embodiment, if collision on one side or the other side of thefront and rear sides of the vehicle is detected by the collisiondetector 2, the supply valve controller 8 on the other side performscontrol for discharging the high voltage unit 3 on one side, and thehigh voltage controller 4 on one side performs control for bringing thehydrogen supply valve 7 on the other side into the closed state. Withthis, in a case where collision occurs on one side of the vehicle, thesupply valve controller 8 which is at a location separated from acollision part on the other side of the vehicle unsusceptible to imageof collision reliably performs control for discharging the high voltageunit 3 on one side. In a case where collision occurs on the other sideof the vehicle, the high voltage controller 4 which is at a locationseparated from a collision part on one side of the vehicle unsusceptibleto image of collision reliably performs control for bringing thehydrogen supply valve 7 on the other side into the closed state. Thatis, even in a case where vehicle collision occurs, it is possible toreliably stop the function of a control target.

In the first embodiment described above, although the high voltage unit3 and the high voltage controller 4 are arranged on the front side ofthe vehicle, and the hydrogen supply unit 5, the hydrogen supply valve7, and the supply valve controller 8 are arranged on the rear side ofthe vehicle, the disclosure is not limited thereto. The high voltageunit 3 and the high voltage controller 4 may be arranged on the rearside of the vehicle, and the hydrogen supply unit 5, the hydrogen supplyvalve 7, and the supply valve controller 8 may be arranged on the frontside of the vehicle.

In a vehicle in which the vehicular fuel cell system 10 is mounted, inorder to extend a cruising distance, the amount of hydrogen stored inthe hydrogen storage tank 51 of the hydrogen supply unit 5 increases,and the tank capacity increases. For this reason, in consideration ofvehicle weight distribution, as described above, the hydrogen storagetank 51 of the hydrogen supply unit 5 and the high voltage unit 3 whichis a different large component are mounted separately on the front andrear sides of the vehicle.

If collision on the front or rear side of the vehicle is detected, thecollision detector 2 transmits the collision signal to the supply valvecontroller 8 on the front side of the vehicle and the high voltagecontroller 4 on the rear side of the vehicle. The high voltagecontroller 4 on the rear side of the vehicle performs control forbringing the hydrogen supply valve 7 on the front side of the vehicleinto the closed state in response to the collision signal from thecollision detector 2. The supply valve controller 8 on the front side ofthe vehicle performs control for discharging the high voltage unit 3 onthe rear side of the vehicle in response to the collision signal fromthe collision detector 2.

Second Embodiment

FIG. 3 is a block diagram showing a schematic system configuration of avehicular fuel cell system 20 according to a second embodiment of thedisclosure. In the second embodiment, a plurality of proximity sensors21 which detect distance information with respect to an object areprovided on the front and rear sides of the vehicle in the periphery ofthe vehicle. The proximity sensors 21 are, for example, ultrasonicsensors, radar sensors, or the like. For example, a pair of proximitysensors 21 are provided near both ends of the front side of the vehicle(a front bumper or the like) and a pair of proximity sensors 21 areprovided near both ends of the rear side of the vehicle (a rear bumperor the like). The locations and the number of proximity sensors 21provided in the periphery of the vehicle are arbitrarily determined aslong as the proximity sensors 21 are respectively provided on the frontand rear sides of the vehicle.

On the front side of the vehicle, a proximity sensor controller 22 whichdetects an approaching location, at which an object approaches thevehicle, based on the distance information from the respective proximitysensors 21 is provided. The proximity sensor controller 22 may beprovided near the vehicle center or on the rear side of the vehicle. Forexample, the proximity sensor controller 22 extracts the proximitysensor 21 having a distance value equal to or less than a predeterminedthreshold among the proximity sensors 21 and detects the location of theproximity sensor 21 as the approaching location of the object. Theproximity sensor controller 22 outputs the detected approaching locationof the object to the collision detector 2. The collision detector 2 mayinclude the proximity sensor controller 22.

For example, if the distance value of the proximity sensor 21 on thefront right side of the vehicle is equal to or less than thepredetermined threshold, the proximity sensor controller 22 detects thefront right side of the vehicle corresponding to the location of theproximity sensor 21 as the approaching location of the object.Similarly, when the distance value of the proximity sensor 21 on therear left side of the vehicle is equal to or less than the predeterminedthreshold, the proximity sensor controller 22 detects the rear left sideof the vehicle corresponding to the location of the proximity sensor 21as the approaching location of the object.

The collision detector 2 detects vehicle collision, for example, if anacceleration of an acceleration sensor (airbag control device) 23becomes equal to or greater than a predetermined value, and determinesthe collision location (front collision on the front side of the vehicleand rear collision on the rear side of the vehicle) of the vehicle basedon the proximity location from the proximity sensor controller 22.

If it is determined that the collision location of the vehicle is frontcollision, the collision detector 2 transmits a front collision signalto the supply valve controller 8 on the rear side. The supply valvecontroller 8 on the rear side performs control for discharging the highvoltage unit 3 on the front side in response to the front collisionsignal from the collision detector 2. While collision on the front sideof the vehicle may cause failure or the like in the high voltagecontroller 4 on the front side of the vehicle, the normal supply valvecontroller 8 on the rear side of the vehicle can reliably performcontrol for discharging the high voltage unit 3 in response to the frontcollision signal from the collision detector 2.

If it is determined that the collision location of the vehicle is rearcollision, the collision detector 2 transmits a rear collision signal tothe high voltage controller 4 on the front side. The high voltagecontroller 4 on the front side performs control for bringing thehydrogen supply valve 7 on the rear side into the closed state inresponse to the rear collision signal from the collision detector 2.

While collision on the rear side of the vehicle may cause failure or thelike in the supply valve controller 8 on the rear side of the vehicle,the normal high voltage controller 4 on the front side of the vehiclecan reliably perform control for bringing the hydrogen supply valve 7into the closed state in response to the rear collision signal from thecollision detector 2.

In the first embodiment described above, if vehicle collision isdetected, both of the discharging control of the high voltage unit 3 andthe shut-off control of the hydrogen supply valve are executed, and bothfunctions of the high voltage unit 3 and the hydrogen supply unit 5 arestopped. On the other hand, in the second embodiment, only the controlon one side, on which collision is detected, between the dischargingcontrol of the high voltage unit 3 on the front side of the vehicle andthe shut-off control of the hydrogen supply valve 7 on the rear side ofthe vehicle is executed by determining the collision location of thevehicle using the proximity sensors 21. With this, it is possible tostop only the function of the side, on which collision is detected,between the high voltage unit 3 on the front side of the vehicle and thehydrogen supply unit 5 on the rear side of the vehicle, and to continuethe function on the side on which collision is not detected. In thesecond embodiment, the same parts as those in the first embodimentdescribed above are represented by the same reference numerals, anddetailed description thereof will not be repeated.

Third Embodiment

FIG. 4 is a block diagram showing a schematic system configuration of avehicular fuel cell system according to a third embodiment of thedisclosure. A vehicular fuel cell system 30 according to the thirdembodiment further includes a traveling determination unit 31 whichdetermines whether or not the vehicle is travelable after vehiclecollision, in addition to the configuration according to the secondembodiment described above.

In a case where collision actually occurs, as described above, it isnecessary to not only stop the function of a required control target,such as the discharging control of the high voltage unit 3, or theshut-off control of the hydrogen supply valve 7, but also quicklyretreat the vehicle from a collision place (a traveling lane of anexpressway, an intersection with heavy traffic, or the like). However,there are a case where retreat traveling should be performed and a casewhere retreat traveling should not be performed according to thelocation of a portion broken due to vehicle collision.

For example, it is assumed that, in a case where a component (a motor, ahigh voltage battery, a PCU, or the like) related to electric traveling(EV traveling), in which a vehicle travels with electric power, isarranged on the front side of the vehicle, collision occurs on the rearside of the vehicle. In this case, since there is a high possibilitythat a component related to electric traveling on the front side of thevehicle is normal, it is possible to retreat the vehicle in a retreattraveling mode or the like. In a case where collision occurs on thefront side of the vehicle, even if a self-diagnosis system determinesthat electric traveling is possible, damage due to collision may remainin any portion of the system (breakage of a sheath of a high voltagewiring causing short-circuiting of a wiring, or the like), and this maynot be detected. In this case, it is determined that retreat travelingis impossible, and retreat traveling should not be performedunreasonably.

Accordingly, in the third embodiment, if the collision detector 2detects collision on the front side, the supply valve controller 8 onthe rear side performs the discharging control for discharging the highvoltage unit 3 on the front side according to a detection result of thecollision detector 2, the traveling determination unit 31 determinesthat the vehicle is in a traveling-disabled state according to thedetection result of the collision detector 2, and a notification unit 32gives notification to the effect that the vehicle is in thetraveling-disabled state. With this, when collision on the front side isdetected, it is possible to give the user notification to the effectthat the vehicle is in the traveling-disabled state, and to preventunreasonable retreat traveling while reliably performing the dischargingcontrol of the high voltage unit 3 on the front side.

FIG. 5 is a flowchart showing a control processing flow of the vehicularfuel cell system according to the third embodiment. The proximity sensorcontroller 22 detects the approaching location, at which an objectapproaches the vehicle, based on the distance information from therespective proximity sensors 21 and outputs the detected approachinglocation to the collision detector 2 (Step S201).

If the acceleration of the acceleration sensor 23 is equal to or greaterthan the predetermined value, the collision detector 2 detects vehiclecollision (Step S202), and determines whether or not the collisionlocation is rear collision based on the approaching location from theproximity sensor controller 22 (Step S203).

If it is determined that the collision location of the vehicle is notrear collision and is front collision (No in Step S203), the collisiondetector 2 transmits the front collision signal to the supply valvecontroller 8 on the rear side (Step S204). The supply valve controller 8on the rear side performs control for discharging the high voltage unit3 on the front side in response to the front collision signal from thecollision detector 2 (Step S205).

If the traveling determination unit 31 determines that the vehicle isswitched to the retreat traveling mode for activating a retreattraveling system (YES in Step S206), the notification unit 32 gives theuser notification to the effect that retreat traveling is impossible(Step S207), and this processing ends. The notification unit 32 is, forexample, a display device (a liquid crystal display, an organic EL, orthe like) in an odometer, a speaker, or the like.

If it is determined that the collision location of the vehicle is rearcollision (YES in Step S203), the collision detector 2 transmits therear collision signal to the high voltage controller 4 on the front sideand the traveling determination unit 31 (Step S208). The high voltagecontroller 4 on the front side performs control for bringing thehydrogen supply valve 7 on the rear side into the closed state inresponse to the rear collision signal from the collision detector 2(Step S209), and this processing ends. At this time, the notificationunit 32 may give the user notification to the effect that retreattraveling is possible.

The disclosure is not limited to the foregoing embodiments, and can beappropriately changed without departing from the disclosure. In thedisclosure, for example, the processing shown in FIG. 2 can be realizedby making a CPU execute a computer program. The program can be storedusing various types of non-transitory computer-readable mediums and canbe supplied to a computer. The non-transitory computer-readable mediumsinclude various types of tangible storage mediums. Examples of thenon-transitory computer-readable mediums include a magnetic storagemedium (for example, a flexible disk, a magnetic tape, a hard diskdrive), a magneto-optical storage medium (for example, a magneto-opticaldisk), a compact disk-read only memory (CD-ROM), a CD-R, a CD-R/W, and asemiconductor memory (for example, a mask ROM, a programmable ROM(PROM), an erasable PROM (EPROM), a flash ROM, and a random accessmemory (RAM)).

The program may be supplied to the computer by various types oftransitory computer-readable mediums. Examples of the transitorycomputer-readable mediums include an electrical signal, an opticalsignal, and an electromagnetic wave. The transitory computer-readablemediums can supply the program to the computer through a wiredcommunication path, such as an electric wire and an optical fiber, or awireless communication path.

What is claimed is:
 1. A vehicular fuel cell system comprising: acollision detector configured to detect collision on front and rearsides of a vehicle; a high voltage unit arranged on one side of thefront and rear sides of the vehicle and having a high voltage; a highvoltage controller arranged on the one side and configured to controlthe high voltage unit; a hydrogen supply unit arranged on the other sideof the front and rear sides of the vehicle and configured to supplyhydrogen to a fuel cell stack; and a supply valve controller arranged onthe other side and configured to control a hydrogen supply valve, thehydrogen supply valve being configured to shut off a supply path ofhydrogen from the hydrogen supply unit to the fuel cell stack, wherein,when collision is detected by the collision detector, the supply valvecontroller on the other side performs discharging control fordischarging the high voltage unit on the one side and the high voltagecontroller on the one side performs shut-off control for bringing thehydrogen supply valve on the other side into a closed state.
 2. Thevehicular fuel cell system according to claim 1, wherein a proximitysensor configured to detect distance information with respect to anobject is provided on each of the one side and the other side in aperiphery of the vehicle, when the collision detector detects collisionon the one side based on the distance information from the proximitysensor on the one side, the supply valve controller on the other sideperforms the discharging control for discharging the high voltage unitaccording to a detection result of the collision detector, and when thecollision detector detects collision on the other side based on thedistance information from the proximity sensor on the other side, thehigh voltage controller on the one side performs the shut-off controlfor bringing the hydrogen supply valve into the closed state accordingto the detection result of the collision detector.
 3. The vehicular fuelcell system according to claim 1, further comprising: a travelingdetermination unit configured to determine whether or not the vehicle isin a traveling-disabled state; and a notification unit configured togive a user notification that the vehicle is in the traveling-disabledstate, wherein, when the collision detector detects collision on the oneside, the supply valve controller on the other side performs thedischarging control for discharging the high voltage unit according to adetection result of the collision detector, the traveling determinationunit determines that the vehicle is in the traveling-disabled stateaccording to the detection result of the collision detector, and thenotification unit gives notification to the effect that the vehicle isin the traveling-disabled state.
 4. The vehicular fuel cell systemaccording to claim 1, wherein the high voltage controller is providedcloser to a vehicle center than the high voltage unit in a front-reardirection of the vehicle.
 5. The vehicular fuel cell system according toclaim 1, wherein the hydrogen supply unit includes a hydrogen storagetank, and the supply valve controller is provided closer to a vehiclecenter than the hydrogen storage tank in a front-rear direction of thevehicle.
 6. The vehicular fuel cell system according to claim 1, whereinthe high voltage unit includes a battery.
 7. A method of controlling avehicular fuel cell system, wherein the vehicular fuel cell systemincludes a high voltage unit arranged on one side of front and rearsides of a vehicle and having a high voltage, a high voltage controllerarranged on the one side and configured to control the high voltageunit, a hydrogen supply unit arranged on the other side of the front andrear sides of the vehicle and configured to supply hydrogen to a fuelcell stack, and a supply valve controller arranged on the other side andconfigured to control a hydrogen supply valve, the hydrogen supply valvebeing configured to shut off a supply path of hydrogen from the hydrogensupply unit to the fuel cell stack, wherein when collision on the oneside or the other side is detected, the supply valve controller on theother side performs discharging control for discharging the high voltageunit on the one side, and the high voltage controller on the one sideperforms shut-off control for bringing the hydrogen supply valve on theother side into a closed state.